Conceptual Physics

Chapter 1 Problems

Conceptual Problems

C.1 Why do scientists not define the standard for the second to be a fraction of a day?

C.2 What are the pitfalls in attempting to convert pounds into kilograms?

C.3 When multiplying by a conversion factor, how do you determine which unit belongs in the numerator and which in the

denominator?

C.4 Can a leg of a right triangle be longer than the hypotenuse? Why or why not?

Yes No

C.5 Consider the sine and cosine functions. (a) As an angle increases from 0° to 90°, does the sine of the angle increase or

decrease? (b) How about the cosine?

(a) Increases Decreases

(b) Increases Decreases

C.6 You walk along the edge of a large circular lawn. You walk clockwise from your starting location until you have moved an

angle of ʌ radians. What geometric shape is defined by the following three points: your starting position, your final position,

and the center point of the lawn?

i. Isoceles triangle

ii. Right triangle

iii. Straight line

Section Problems

Section 2 - Prefixes

2.1 How many centimeters are there in a kilometer?

cm

2.2 A carbon-carbon triple bond has a length of 120 picometers. What is its length in nanometers?

nm

2.3 The 2000 Gross Domestic Product of the United States was $9,966 billion. If you were to regard the dollar as a scientific unit,

how would you write this using the standard prefixes?

i. 9966

ii. 9.966

iii. 99.66

i. pico

ii. milli

iii. kilo

iv. tera

dollars

2.4 A gremlin is a tiny mythical creature often blamed for mechanical failures. Suppose for a moment that a shrewd physicist

catches one such gremlin and makes it work for her instead of against her. She determines that the gremlin can produce 24

milliwatts of power. How many gremlins are required to produce 24,000 megawatts of power?

gremlins

2.5 A drug company has just manufactured 50.0 kg of acetylsalicylic acid for use in aspirin tablets. If a single tablet contains 50 0

mg of the drug, how many tablets can the company make out of this batch?

tablets

2.6 The diameter of an aluminum atom is about 0.24 nm, and the nuclear diameter is about 7.2 fm (femtometer = 10í^15 meter).

(a) If the atom's diameter were expanded to the length of an American football field (91.44 m) and the nuclear diameter

expanded proportionally, what would be the nuclear diameter in meters? (b) Is the saying that "the atom is mostly empty

space" confirmed by these figures?

(a) m

(b) Yes No

Section 3 - Scientific notation

3.1 An electron can tunnel through an energy barrier with probability 0.0000000000375. (This is a concept used in quantum

mechanics.) Express this probability in scientific notation.

(^20) Copyright 2007 Kinetic Books Co. Chapter 1 Problems